The HTML specification up to version 4, does not allow you to upload files without page post, you need to rely on server code to get the amount of data uploaded, however HTML5 specification comes with new features for XMLHttpRequest known as XMLHttpRequest2.
There's an upload property for XMLHttpRequest in which you can have access to some client-side events for uploading data, like onprogress, onload and so forth.
you can read it here:
http://www.html5rocks.com/en/tutorials/file/xhr2/